MicroRNAs in colorectal cancer: A comparative analysis of circulating and tissue microRNA levels

Colorectal cancer (CRC) is one of the most common cancers worldwide. The gold standard screening methods for early detection and monitoring are colonoscopy and stool-based tests. However, innovative and minimally invasive biomarkers need to be integrated into clinical practice.

To identify circulating microRNAs as potential CRC biomarkers through a comparative analysis of tissue and plasma samples from patients with CRC.

This case-control study conducted a quantitative real-time polymerase chain reaction analysis of 84 microRNAs in tumoral and peritumoral tissues, and 179 microRNAs in plasma from 19 patients with CRC. A control cohort for the tissue analysis and another control cohort for the plasma analysis have been enrolled.

In total, 14 microRNAs were significantly differentially expressed in the tissue and plasma samples. Notably, five microRNAs (miR-26b-5p, miR-101-3p, miR-30d-5p, miR-107, and miR-21-5p) presented the same trend in terms of fold change in both types of biological samples. Significant associations between the circulating levels of miR-21-5p and miR-26b-5p and lymphovascular invasion were found.

These five microRNAs with significantly altered levels in plasma and tumoral tissue, could be good non-invasive CRC biomarkers candidates, enhancing screening, and supporting precision and individualized patient care.